Remediation of Superfund and other hazardous waste sites requires the significant use of monitoring procedures to ensure that environmental conditions required for bioremediation or chemical degradation of specific toxicants are present, and to verify that pollutant removal is occurring. Microelectrodes (tip diameters of l-10 femtomoles, Fm) can be used to make such measurements in a laboratory under highly controlled conditions, but none are commercially available for use in the environment. The goal of this Phase I SBIR is to develop self-contained microelectrodes to be used in the environment to monitor a variety of constituents in contaminated soils and sediments. These devices will contain a new type of microelectrode connected intimately to a microelectronic circuit for amplifying, processing, and transmitting microelectrode signals. Initially, the microelectrodes will be for dissolved oxygen (amperometric), pH and ammonium (potentiometric) and redox-potential, ORP (conductimetric). The techniques will then be modified in Phase II to make a myriad of other microelectrodes. These devices can be used at Superfund sites to monitor the remediation progress, to verify that proper operating conditions are in place, and to ensure that the toxic chemicals are being effectively removed or detoxified, leading to a minimization of public health threats from the Superfund site.